Before the retrofit, the machine was increasingly unreliable. The safety system frequently generated faults, the press beam was sinking on cylinder Y2, and relays in the electrical cabinet had to be replaced regularly.
In addition, the existing safety controller was technically outdated. For safety-related control parts assessed according to EN ISO 13849-1, a typical mission time of 20 years is assumed. For a machine built in 2005, this meant that the relevant safety-related control components had to be reassessed and renewed.
The overall situation initially led the operator to purchase a new machine. Later, the decision was made to bring the existing press brake back into operation with a limited and cost-effective retrofit scope. The objective was not a complete rebuild, but a functional and safe machine with a clearly defined retrofit scope.
Concept: Cost-Optimised Basic Retrofit Scope
The scope was defined so that the machine could be operated reliably and safely again, without additional work that was not required for this objective.
The main measures were:
- The existing Delem control was replaced with a Delem DA-58Tx.
- The components in the electrical cabinet were renewed; only the backgauge axis drives remained.
- An AKAS system was installed as the protective device for the press beam.
- The safety-related integration was implemented using a Fiessler FMSC safety controller.
- The hydraulic blocks were inspected and completely overhauled.
Fiessler offers AKAS and FMSC as a safety solution designed for press brakes. The combination of AKAS, FMSC and Delem control is suitable for a cost-conscious control retrofit on existing press brakes.
The overhaul of the hydraulic blocks also eliminated the sinking of the press beam on Y2.
Implementation
The implementation required more effort than initially expected. The circuit diagrams supplied by the manufacturer only partly matched the actual machine. This made the planning more difficult and required additional checks directly on the machine.
The Fiessler FMSC safety controller was also used for the first time in this project. This required some familiarisation. The communication with the Delem control also had to be adjusted and tested during commissioning.
After commissioning, the combination of Fiessler AKAS, Fiessler FMSC and Delem control retrofit proved to be a practical solution for this type of retrofit.
The result is a functionally stable, safety-related renewed and economically implemented retrofit of the existing press brake.
